1. Field of the Invention
The invention relates generally to an interface for a lamp operating device, in particular for a ballast for a gas discharge lamp, to lamp operating devices having such interfaces and to methods of generating control commands, in particular dimming commands for a lamp operating device.
A user should thus be provided with the possibility of entering manually, via a digital interface, control commands, in particular dimming commands for an electronic ballast.
2. Description of the Related Art
From EP 0 641 148 A1 it is generally known to carry out a dimming of an electronic ballast for supplying a load, such as for example a lamp, by means of an analogue phase control technique.
There is also known from German patent application 197 08 784 an electronic ballast which has (in the configuration according to FIG. 7) an interface device. This interface device can thereby be controlled via key signals or switch signals, as also via digital control signals. In the case of a connected key device, a connected electronic ballast can then be switched on or switched off by a (short or long) key press. In the same manner, however, a DSI (Digital Signal Interface) operation is also possible with which certain digital commands transmit for example desired values for brightness regulation etc.
With the interface device known from DE 197 08 784 it is disadvantageous that upon connection to an interface device of a key or switch supplied with mains voltage the user must select that duration of actuation of the key or switch which corresponds to the dimming value desired by the user. In other words, the user must mentally convert a dimming value into an actuation duration for the key or switch.